leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
mainlining shenanigans
1,011,980 Commits 2 Branches 0 Tags 5.1 GiB
C 97.7%
Assembly 1.1%
Shell 0.4%
Makefile 0.3%
Python 0.2%
Other 0.1%
f5c7e8425f
Go to file
Vitaly Kuznetsov f5c7e8425f KVM: nVMX: Always make an attempt to map eVMCS after migration 
When enlightened VMCS is in use and nested state is migrated with
vmx_get_nested_state()/vmx_set_nested_state() KVM can't map evmcs
page right away: evmcs gpa is not 'struct kvm_vmx_nested_state_hdr'
and we can't read it from VP assist page because userspace may decide
to restore HV_X64_MSR_VP_ASSIST_PAGE after restoring nested state
(and QEMU, for example, does exactly that). To make sure eVMCS is
mapped /vmx_set_nested_state() raises KVM_REQ_GET_NESTED_STATE_PAGES
request.

Commit f2c7ef3ba9 ("KVM: nSVM: cancel KVM_REQ_GET_NESTED_STATE_PAGES
on nested vmexit") added KVM_REQ_GET_NESTED_STATE_PAGES clearing to
nested_vmx_vmexit() to make sure MSR permission bitmap is not switched
when an immediate exit from L2 to L1 happens right after migration (caused
by a pending event, for example). Unfortunately, in the exact same
situation we still need to have eVMCS mapped so
nested_sync_vmcs12_to_shadow() reflects changes in VMCS12 to eVMCS.

As a band-aid, restore nested_get_evmcs_page() when clearing
KVM_REQ_GET_NESTED_STATE_PAGES in nested_vmx_vmexit(). The 'fix' is far
from being ideal as we can't easily propagate possible failures and even if
we could, this is most likely already too late to do so. The whole
'KVM_REQ_GET_NESTED_STATE_PAGES' idea for mapping eVMCS after migration
seems to be fragile as we diverge too much from the 'native' path when
vmptr loading happens on vmx_set_nested_state().

Fixes: f2c7ef3ba9 ("KVM: nSVM: cancel KVM_REQ_GET_NESTED_STATE_PAGES on nested vmexit")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210503150854.1144255-2-vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-07 06:06:11 -04:00
arch KVM: nVMX: Always make an attempt to map eVMCS after migration 2021-05-07 06:06:11 -04:00
block cgroup: rstat: punt root-level optimization to individual controllers 2021-04-30 11:20:37 -07:00
certs integrity-v5.13 2021-05-01 15:32:18 -07:00
crypto for-5.13/drivers-2021-04-27 2021-04-28 14:39:37 -07:00
Documentation doc/kvm: Fix wrong entry for KVM_CAP_X86_MSR_FILTER 2021-05-07 06:06:11 -04:00
drivers - Improve scalability of DM's device hash by switching to rbtree 2021-05-01 11:34:03 -07:00
fs orangefs: implement orangefs_readahead 2021-05-02 14:13:46 -07:00
include Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-05-02 09:14:01 -07:00
init integrity-v5.13 2021-05-01 15:32:18 -07:00
ipc fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
kernel Add Landlock, a new LSM from Mickaël Salaün <mic@linux.microsoft.com> 2021-05-01 18:50:44 -07:00
lib ARM: 2021-05-01 10:14:08 -07:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
mm mm/memory-failure: unnecessary amount of unmapping 2021-04-30 11:20:44 -07:00
net RDMA merge window pull request 2021-05-01 09:15:05 -07:00
samples Add Landlock, a new LSM from Mickaël Salaün <mic@linux.microsoft.com> 2021-05-01 18:50:44 -07:00
scripts scripts: a new script for checking duplicate struct declaration 2021-04-30 11:20:35 -07:00
security Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-05-02 09:14:01 -07:00
sound sound updates for 5.13 2021-04-30 12:48:14 -07:00
tools Add Landlock, a new LSM from Mickaël Salaün <mic@linux.microsoft.com> 2021-05-01 18:50:44 -07:00
usr Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
virt kvm: exit halt polling on need_resched() as well 2021-05-03 11:25:36 -04:00
.clang-format cxl for 5.12 2021-02-24 09:38:36 -08:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-04-25 05:17:02 +09:00
.mailmap It's been a relatively busy cycle in docsland, though more than usually 2021-04-26 13:22:43 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS - Core Frameworks 2021-04-28 15:59:13 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Add Landlock, a new LSM from Mickaël Salaün <mic@linux.microsoft.com> 2021-05-01 18:50:44 -07:00
Makefile integrity-v5.13 2021-05-01 15:32:18 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.